Known in dental implantology, for the preparation of an implant bed, is the practice of using a set of a plurality of differing dental drills, which set comprises, for example, a milling cutter, a pilot drill, a profile drill, a spiral drill (also twist drill) and a threading tap drill.
Broadly, the procedure in the preparation of an implant bed is as follows: Firstly, the bone surface is exposed, and smoothed by means of a milling cutter. The implantation site is marked by means of the milling cutter, and possibly widened, in which latter case a plurality of milling cutters of increasing diameters are used. The implant bed is then prepared by means of appropriate pilot drills, in order to determine the drilling axis. The drilled hole is widened to the required size by means of spiral drills. A profile drill is used to match the profile of the drilled hole to the shape of the provided implant. In a terminal step, an internal thread is then realized in the drilled hole by means of a threading tap drill.
In order to ensure an optimum implantation axis, a drilling template is usually used for the preparation of the implant bed. Such drilling templates serve to guide dental drills and to prevent slipping or deviation errors during the drilling process. A drilling template is designed in such a way that it can be used for the preparation of one or more implantation sites. It has one or more drilling holes, into which the dental drills are inserted prior to drilling. Frequently, standardized metal drill sleeves are inserted into the drilling holes of the drilling template, for example by being polymerized or pressed in, in order further to increase the precision of the drilling. Such a method is disclosed, for example, in WO 99/26540.
In the course of the drilling process, it is usually necessary for the drilling holes or drill sleeves in the drilling template to be matched, through use of corresponding reduction sleeves, to the diameter of the dental drill being used at a given time. Alternatively, appropriate drilling spoons (also drill handles) can be inserted into the drilling holes or drill sleeves. Thus, an entire set of differing reduction sleeves or drilling spoons is required for the complete preparation of a single implant bed. Because the reduction sleeves or drilling spoons must be exchanged continually, this results in increased complexity and potential for error.
Moreover, in the case of individual dental drills, particularly in the case of profile drills, it can be the case that these drills are too broad for a reduction sleeve or drilling spoon. In this case, the drilling has to be performed without guidance, and the risk of a drilling inaccuracy is significantly greater.